Chair with reclinable seat

ABSTRACT

A seat which is mounted between two side frames, each having a horizontal member and vertical leg members, wherein the seat pivots about a transverse torsion bar extending within said seat width; a structural member extending alongside the torsion bar transferring the torsion bar forces to the frames horizontal members, the structural member having travel limiting means thereon to define the pivoting limits of the seat, the torsion bar being rigidly secured at its ends to the seat and rigidly secured at a point within its ends to the structural member.

DESCRIPTION OF THE PRIOR ART

[0001] Chairs of the abstract description are unknown, but recliningmechanisms seats having torsion bar(s) are common in office-type chairs.When utilizing a torsion bar in an office-type chair, the elongated axisof the bar is usually located above the chair post within a mechanismthat also contains the seat rotation stops and the seat initialresiliency controls. Typical office chairs having a torsion barmechanism are described in U.S. Pat. No. 3,136,580; 3,240,528 and3,224,807, among others.

[0002] The only four legged chairs known to the applicant that have atorsion bar mechanism, are disclosed in the U.S. Pat. No. 4,938,532titled “Seating apparatus”, and in the U.S. Pat. No. 5,902,912 titled“Chair with movable back”

[0003] In the chair of U.S. Pat. No. 4,938,532, the torsion bar, itsbearings and the back stops are mounted on an aluminum extruded bar thatis welded to the chair frame. Here the torsion bar is used to provide aflexible back support, only.

[0004] In the chair of U.S. Pat. No. 5,902,012 the ends of the torsionbar are engaged to the back board rotation limits, while the occupantload is absorbed by the fixed seat horizontal board.

[0005] Here also, the torsion bar is used to provide a flexible backsupport, only.

BACKGROUND OF THE INVENTION

[0006] This patent application is a continuation-in-part of my U.S. Pat.No. 6,168,233 B1, titled “Reclinable seating using a torsion bar”,issued Jan. 2, 2001.

[0007] The present invention relates to seating apparatus which can bein the form of a seat, a chair, sofa or other appliance which is usedfor seating purposes.

[0008] Here, an inner structure including the bottom seat board and theback board pivots (rotates)—as a unit—within a chair frame. Elastictorsion means allows said inner structure to rotate between establishedforward and rear positions in relation thereto said chair frame, makingthe chair more comfortable to users.

[0009] In this invention, a torsion bar is guided and supported by aseries of bushings housed inside tubes; in turn the tubes are supportedby a flat piece of metal that extends across the width of the chair,attaching the horizontal members of the side frames. An adjustabletorsion bar anchor situated about the center of the torsion bar providesthe initial resilient torque. All of above elements: the tubes, thebushings and the torsion bar, plus the anchor controls, are placed ontosaid piece of metal, that will further be referred as the “structuralmember”.

[0010] What is new is the concept of having four legged (or sled), typechairs having reclinable seating, up to now the exclusive province ofoffice chairs having a reclining mechanism at the top of a center post.But these chairs are too expensive and/or cumbersome to move and tostore-away, to be used in high density areas like restaurants,auditoriums, catering halls, etc.

[0011] In view of the shortcomings mentioned above, it is the principalobject of the present invention to introduce a chair having a reclinableseat disposed in a four legged frame, or a sled frame, whereby saidframe could be made of plastic, metal and/or wood.

[0012] Yet, another object of the invention is to provide an inexpensivereclinable chair having enhanced aesthetics and comfort.

[0013] A further object of the invention is to provide a simplifiedmethod of manufacturing and assembling such chairs.

BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In the accompanying drawings:

[0015]FIG. 1 is a perspective view of a four legged reclinable woodenchair according to the present invention,

[0016]FIG. 2 is a schematic side elevational view of the chair shown inFIG. 1, with the seat in the fully upright position,

[0017]FIG. 3 is a schematic side elevational view of the chair shown inFIG. 1, with the seat in an fully reclined position,

[0018]FIG. 4 is an exploded partial perspective view of the seat frameof FIG. 1,

[0019]FIG. 5 is a schematic sectional view of FIG. 4 taken along lineA-A,

[0020]FIG. 6 is a partial schematic sectional view of FIG. 4 taken alongline B-B, with the seat frame in the fully upright position,

[0021]FIG. 7 is a partial schematic sectional view of FIG. 4 taken alongline B-B, showing the seat frame in a fully reclined position,

[0022]FIG. 8 is a schematic sectional view of FIG. 4 taken along lineC-C, showing the torsion bar control mechanism,

[0023]FIG. 9 is a schematic sectional view of the seat frame of FIG. 2,taken along line D-D, showing another embodiment of the invention,

[0024]FIG. 10 is a schematic sectional view of the seat frame of FIG. 3,taken along line E-E, showing another embodiment of the invention,

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0025] Referring now in detail to the embodiments of the chair shown inFIG. 1 which comprises a supporting wooden frame incorporating a pair ofside frames, each side frame having a substantially horizontal member 12and substantially vertical leg members 11. A front cross-rail 13, and arear cross-rail 22 connect both side frames in a spaced apartrelationship.

[0026] The seat comprises an upholstered bottom board 17, mounted on theseat frame 14 and an upholstered back board 16, which are connected toeach other at an obtuse angle by the back support 15. The upholsteryconsist of contoured foam blocks that are glued onto the bottom and backboards and are subsequently covered by fabrics.

[0027] The seat frame 14 is—usually—an open structure comprising four ormore wooden elements, glued and/or nailed together. The seat pivot(rotate) as a unit about a virtual axis T-T, in response to a backwardleaning movement of the chair occupant, as shown in FIG. 3.

[0028] It will be understood that the hardware is symmetrically disposedon both side of the chair; hence, the hardware on one side only will bedescribed.

[0029]FIG. 4 is an exploded perspective view of the chair shown inFIG. 1. Here the chair frame has been vertically displaced from theseat, and for clarity purposes the bottom seat fabric, the foam 29 andthe foam support board 30 are not shown.

[0030] The bottom seat board comprises a wooden frame 14, attached bythe back support 15 to the upholstered back 16. 19 is the tube(s) thathouses the square torsion bar 25, while 24 is a metallic insert todistribute the bar torsion moment over a larger surface of the frame,usually made of soft woods. 20 is a torsion bar rotatable anchor thatadjust the initial resilience of the torsion bar, and 21 is the anchoradjusting screw.

[0031]18 is the structural member in the shape of a bent metal plate towhich the tube 19 is welded; the ends of said member—shown hereprotruding beyond the frame 14 side—is attached to the underneath of thehorizontal members 12, by means of screws 23.

[0032] Numeral 35 is a cut out on the seat frame that is necessary foranother embodiment of this invention.

[0033]FIG. 5 shows a cross section of the reclining mechanism. Here thebent structural member 18 is shown fastened to the horizontal members 12by the fasteners 23.

[0034] The torsion bar 25 extends within the seat frame 14 and attachedto it through the metallic inserts 24. The torsion bar is held in placeby the four plastic bushings 32, that in turn are housed inside thetubes 19; the tubes are welded to the structural member 18.

[0035] Numeral 20 is the initial torsion bar resilience adjuster.

[0036]30 is the foam board, a thin piece of plywood to distribute theload on the foam 29 over the structure of frame 14.

[0037] In this embodiment, any reclining of the seat is transmitted toboth ends of the torsion bar 25 by ways of inserts 24 and frame members14.

[0038] The torsion bar would had rotated freely if not for the presenceof the adjustable anchor 20 that is mounted firmly on the torsion baritself; said anchor 20 being rigidly connected to the structural member18 by the adjusting screw 21.

[0039] Hence, any seat rotation will twist the ends of the torsion barthat are securely attached to the seat frame 14, while the center of thetorsion bar remains fixed in a desired relationship with the chair sideframes. The torsion bar twisting creates the reactive resilience torquethat will bias the seat to its upright position.

[0040] The two extreme positions of the seat: fully upright and fullyreclined are achieved by limiting the degree of rotation of the seatframe 14.

[0041] To that effect, a plurality of elastic stops mounted on thestructural member 18, and placed underneath the seat frame 14, willelastically stop the seat frame rotation at pre-established positions.

[0042] In FIG. 6, 26 is a front stop, a rubber bumper attached to thestructural member 18; it is placed forward of the torsion bar axis andunderneath the seat frame 14, hence stopping the counter-clockwiserotation of the seat frame at its maximum upright position. Not shown:the tube 19 is solidly welded at some places to the structural member18. The word front on the drawing indicates the position of the seatfront.

[0043] In FIG. 7, the seat frame 14 is stopped by the rear stop 27, arubber bumper that is attached to the structural member 18; here thestop prevents the seat frame 14, and hence the seat, from going fartherthan a pre-established maximum reclined position.

[0044]FIG. 8 is a cross-sectional view of the mechanism for adjustingthe initial resilience of the torsion bar. Here, 19 is the tube; 25 isthe torsion bar that goes through a corresponding opening in thealuminum extrusion of which the anchor 20 is built, 34 is a rotary jointto accommodate the anchor's different positions in relationship with themember 18, and 21 is the adjusting screw.

[0045] By tightening up the screw 21, the torsion bar is twistedcounter-clockwise, and the initial resilience increases, biasing theseat harder against the elastic front seat stops 26. Likewise, anybackwards tilting of the seat by an occupant, will only increase thetwisting of the bar, further increasing the seat resistance to pivotbackwards.

[0046] In another embodiment of the present invention, the seatrotations are limited by the interacting of means disposed in the seatframe with means disposed in the chair side frames. In a wooden chairsimilar to the one shown in FIG. 2 but having this new embodiment, theseat stops would not be placed on the structural member 18, that couldthen be built narrower. To that effect, FIG. 9 is a schematic sectionalview of the seat frame of FIG. 2, taken along line D-D, showing this newembodiment in place. Here, 12 is the side frame and 14 is the seatframe. 31 is a narrow ‘L’ shaped metal bracket rigidly attached to theside frame 12 that enters into the opening of the window 35, a cut outinto the seat frame 14 (also, see numeral 35 in FIG. 4), having elasticstops 32 and 33 glued onto the lower and upper walls of the window.

[0047] With the seat at its maximum upright position—as shown in FIG.2—the seat frame 14 is almost parallel to the side frame 12, and thebracket 31 is pressed against the upper elastic stop 33, effectivelystopping any further counter clockwise rotation of the seat originatedby the torsion bar bias and/or the chair occupant weight.

[0048]FIG. 10 shows a chair similar to the one shown in FIG. 3 whereby,the reclining seat is stopped at its maximum reclinable position by thebracket 31 acting against the lower elastic stop 32.

What I claim is: 1) A chair having a reclinable seat comprising incombination two supporting side frames, each having at least onesubstantially horizontal member and substantially vertical leg members,said frames disposed in a spaced apart relationship by cross-rails; aplurality of travel limiting means placed within said side frames, and aseat mounted within said side frames for pivoting about a transverseaxis defined by resilient means extending within said seat, and astructural member disposed alongside said resilient means and attachedto said horizontal members; means placed onto the structural member tohold and guide said resilient means, and means for securing in anonrotatable relation said resilient means ends to said seat, adjustablemeans for locking in a desired nonrotatable relation said resilientmeans at a point intermediate its ends to said structural member, andmeans positioned on said seat engaging said travel limiting meansdisposed within said side frames members further defining the positionof maximum rearward pivoting of the seat and the position of maximumforward pivoting position of the seat, whereby said resilient means urgesaid seat toward its maximum forward position. 2) A chair having areclinable seat comprising in combination two supporting side frames,each having at least one substantially horizontal member andsubstantially vertical leg members, said frames disposed in a spacedapart relationship by cross-rails, and a seat mounted within said sideframes for pivoting about a transverse axis defined by resilient meansextending within said seat, and a structural member disposed alongsidesaid resilient means and attached to said horizontal members; meansplaced onto the structural member to hold and guide said resilientmeans; the structural member having a plurality of travel limiting meansinteracting with said seat thereon further defining the pivoting limitsof the seat, and means for securing in a nonrotatable relation saidresilient means ends to said seat; adjustable means for locking in adesired nonrotatable relation said resilient means at a pointintermediate its ends to said structural member, whereby said resilientmeans urge said seat toward its maximum forward position. 3) A chairhaving a reclinable seat comprising in combination two supporting sideframes each side frame having at least one substantially horizontalmember and substantially vertical leg members, said frames disposed in aspaced apart relationship by cross-rails, and a seat mounted betweensaid side frames pivoting about a transverse torsion bar extendingwithin said seat; a structural member extending alongside the torsionbar having means for transferring the torsion bar forces to saidhorizontal members, and said structural member having a plurality oftravel limiting means interacting with said seat thereto furtherdefining the pivoting limits of the seat, and means for securing in anonrotatable relation the torsion bar ends to said seat, means forsecuring in an adjustable nonrotatable relation the torsion bar at apoint intermediate its ends to said structural member, whereby, saidtorsion bar supports and positions said seat. 4) In a chair as describedin claim 3, whereby the means for securing in an adjustable nonrotatablerelation the torsion bar to said structural member further including apivotably anchor securely engaged to said torsion bar, and an adjustablescrew engaging said structural member to a rotary joint connectedthereto the anchor 5) In a chair as described in claim 1 whereby, saidmeans positioned on said seat engaging said travel limiting meansdisposed within said side frame members further comprising elastic stopsmeans disposed within said seat and seat stop brackets disposed withinsaid side frames. 6) In a chair as described on claims 1 and 2, wherebythe resilient means comprises a square cross section torsion bar.